[v0.2.7] Documentation: API reference and usage guides

[m96-chan]

Summary

Create comprehensive documentation for PyGPUkit v0.2.7.

Tasks

• API reference (docstrings for all public functions)
• Usage guides for common patterns
• Migration guide from v0.2.x
• Performance tuning guide (TF32, FP16, CUTLASS)
• Scheduler/Multi-LLM usage examples
• JIT kernel development guide

Deliverables

• Updated docstrings in source
• docs/ folder or GitHub Pages (optional)
• README updates as needed

References

• README.md v0.2.7 goals: "documentation"

[m96-chan]

Completed in PR #76

Documentation Created

File	Description
docs/getting-started.md	Installation, quick start, basic usage
docs/api.md	Complete API reference with examples
docs/llm.md	SafeTensors, Tokenizer, GPT-2 model guide
docs/performance.md	TF32, FP16, CUTLASS optimization
docs/scheduler.md	Multi-LLM concurrent execution

README Updates

• v0.2.7 feature summary
• LLM module documentation
• API stability section

Files Changed

• docs/getting-started.md (new)
• docs/api.md (new)
• docs/llm.md (new)
• docs/performance.md (new)
• docs/scheduler.md (new)
• README.md (updated)